Tool for plugging high pressure pipes, etc.



A ril 8, 1958 F. H. MUELLER EI'AL 2,829,429

TOOL FOR PLUGGING HIGH PRESSURE PIPES, ETC

Filed Aug. 22, 1951 2 Sheets-Sheet l 72 M 72 gulf; 6; 30' 62 9 4 6'4 /32 Q 4 70 is INVENTORJS.

Frank MueZEeJ;

ATTORNEYS April 1958 F. H. MUELLER ETAL 2,829,429

TOOL FOR PEUGGING HIGH PRESSURE PIPES, ETC

Filed Aug. 22, 1951 2 Sheets-Sheet 2 John .7. Smith INVENTO J l Zfisanic JilMucZZezg'? ATTORNEYS.

TOOL FOR PLUGGING HIGH PRESSURE PIPES, ETC.

Frank H. Mueller and John J. Smith, Decatur, 11]., as-

signors to Mueller Co., Decatur, lll., a corporation of Illinois Application August 22, 1951, Serial No. 243,151

4 Claims. (Cl. 29-213) This invention relates to a machine or tool for inserting or extracting nipples in pipes, plugs in nipples or Ts connected to a" pipe, valve stems in valve Ts connected to a pipe, etc. all while such pipes are in service.

Previous machines for this purpose are illustrated and described in United States Patents Nos. 1,701,691 to Mueller et al., granted February 12, 1929, and 1,996,345 to Frank H. Mueller, granted April 2, 1935. Reference is made to these patents, and particularly to the latter patent, for a more detailed description of methods and apparatus for drilling and plugging mains and pipes, and inserting and removing such plugs while the main is in service.

The tools and apparatus disclosed in the above-mentioned patents, while satisfactory for their intended purpose, give rise to diificulties when the mains or pipes being operated upon are under high pressure. The tools illustrated in these patents consist essentially of a barrel having one end thereof adapted to be connected fluid-tight to one end of a valve, while the other end of such valve is connected to the pipe, or nipple, etc., being operated upon. A plunger or rod extends in fluid-tight relation through the other end of the barrel and is both reciprocable and rotatable within the latter. Such plungerhas, at its forward end, means for holding a plug or a nipple so that the latter may be advanced by the plunger through the valve into engagement with the interior nipple threads, or interior pipe threads, etc. Rotation of the plunger then serves to screw the plug or nipple into the nipple, or pipe, etc. As will be seen, during such operations the interior of the barrel is subject to the same pressure existing in the line. Therefore, line pressure tends to force the plunger rearwardly out of the barrel.

In case of very high line pressure, difficulty is had in manually forcing the plunger forwardly into the barrel to engage the threads on the plug with the threads on the nipple.

Hence, it is an object of the invention to provide an apparatus of the type under consideration in which little manual effort is required to force the plunger forwardly into the barrel against high pressure.

It is another object of this invention to provide apparatus of the type under consideration in which the prasure within the barrel is used to substantially balance or counteract the pressure force on the plunger acting to urge the same in an outward or rearward direction.

It is a further object of this invention to provide a simple, and therefore, inexpensive, apparatus of the type under consideration for accomplishing the above objects.

Other objects and advantages of this invention will be evident from the following description and accompanying drawings, in which:

Figure 1 is an elevational view, partly in section, showing a tool embodying this invention operatively connected to a nipple, projecting from a pipe line, for plugging the nipple.

Figures 2, 3 and 4 are sectional views taken on the corresponding section lines of Figure l.

nited States Patent sure.

Figure 5 is an enlarged vertical sectional view corresponding to Figure 1 but showing the position of the parts when the plug engages the nipple.

Figure 6 is an elevational view, corresponding to Figure 1, but taken 90 thereto.

Although this invention will be described with reference to the plugging of a nipple, it will be realized that the invention is applicable for the purpose of extracting plugs from nipples, or for inserting or extracting plugs in or from Ts, nipples in or from mains, stems in or from valve Ts, and other similar uses.

Referring now to the drawings, there is shown in Figure 1 a section of a pipe line 10 having a nipple 12 welded, or otherwise suitably secured, laterally thereon. Threadedly secured to the upper end of the nipple 12 is a valve 14, conventionally of the gate type as shown, and threadedly secured to the upper end of the valve 14 is an adapter element 16. The pipe line 10 has been tapped within the nipple 12, as shown at 18 in Figure 5, by a drilling machine (not shown), so that the interior of the nipple 12, and the valve 14, are subject to line pres- The upper end of the nipple 12 is interiorly threaded, as at 20, and, for the purpose of illustrating this invention, it is desired to plug the nipple.

For this purpose, a tool 22 embodying this invention is shown connected to the upper end of the adapter element 16. The tool 22 consists of an open-ended tubular member or barrel 24 having exterior threads 26 at its lower end and a wrench-receiving nut-like enlargement 28 immediately thereabove for threadedly connecting the barrel to the upper end of the adapter 16. A plunger or rod 30 of uniform diameter sealingly extends through the upper end of the barrel 24 for reciprocation and rotation within the latter. The lower end of the plunger 30 has a socket 32 provided with right-hand threads 34 and in which is threadedly mounted an inserting adapter 36. The lower end of the adapter shank 38 is provided with a reduced portion having right-hand exterior threads 40 for carrying an exteriorly threaded plug 42 having a. threaded socket 44. The inserting adapter 36 is described more in detail in the aforementioned Patent No. 1,996,345. Hence, a detailed description of its operation is deemed unnecessary here. The bottom of the N plunger socket 32 has a reduced left-hand threaded socket 46 for carrying an extracting adapter, not shown, but likewise described in greater detail in Patent No. 1,996,345.

From the above construction, it can be seen that downward or forward movement of'the plunger 30 will engage the threads of the plug 42 with the interior threads 20 of the nipple 12, and that subsequent rotation of the plunger by the handled ratchet device 48 will serve to thread the plug tightly into the nipple. After the nipple has been plugged, reverse rotation of the plunger 30 will unthread the adapter 36 from the plug 42 for retraction of the plunger and removal of the tool 22, adapter element 16, and 'valve 14.

Since the interior of the barrel 24 is subject to line pressure, there is an upward force acting on the plunger 36 equal to line pressure multiplied by the cross-sectional area of the plunger. In order to overcome and substantially balance or counteract this upwardly directed force,

the barrel 24 is formed in two sections, a lower section 50 having a bore 52 therethrough slightly larger than the diameter of the plunger 30, and an upper section 54 threadedly connected to the lower section 50, locked thereto by a set screw 55, and having an interior bore 56 somewhat larger than the diameter of the plunger. That portion of the plunger 30 reciprocable within the upper section 54 of the barrel is provided with an annular enlargement 58 having an annular circumferential groove 60 in which is mounted a packing 62, herein illustrated as grooved, as at 64, and packing, in the form of O-rings 66 and 68, is mounted in these grooves 63 and 64, respectively,.in order to provide a fluid-tight seal at these points between the plunger 30 and the barrel 24-.

A longitudinal passageway 70 extends from a point adjacent'the lower end of the plunger 30 rearwardly therethrough to a point immediately above the annular enlargement 58. Lateral ports 72 and 74 in the plunger 30 at the opposite end of the passageway 70' provide communication, via the passageway, between the interior of the bore 56 above the piston or enlargement 58 and the interior of the bore 52 below the packing 68. The ports 72 are counterbored somewhat, .as shown best in Figures 2 and 5, to assure communication between the passageway 70 and the bore 56 above the piston 58 when the plunger is in its rearwardmost position, as shown in Figure l. A lateral port 76 is provided in the lower section 59 of the barrel, adjacent the lower edge of the upper section 54, in order to vent the bore or cylinder 56,- forwardly of the piston 58, to the atmosphere.

From the above construction, it can be seen that line pressure enters the cylinder 56-above the piston 58 and exerts a downward force on the latter. The effective area exposed to line pressure exerting a force tending to move the plunger 30 rearwardly is equal to the crosssectional area of the plunger. It will be seen, however, that the upper or rearward face of the piston 58 constitutes an annular area exposed toline pressure tending to force the plunger 30 in a downward or forward direction, since the other or forward face of the piston is exposed to atmospheric pressure. Therefore, the pressure force tending to force the plunger 30 outwardly is counterbalanced or counteracted by the oppositely directed pressure force on the piston 58. In actual practice, the area of the piston exposed to line pressure is somewhat less than the cross-sectional area of the plunger, so that some manual effort is required to force the plunger downwardly for engaging the plug 42 with 'the nipple 12. Such manual effort is of substantially no consequence, however, because of the counteracting force exerted by the piston.

the rearward ends of said sections; piston means on said plunger cooperating with the interior walls of said rearward section; a longitudinal passageway in said plunger having lateral ports providing communication between theinterior of said rearward section rearwardly of said piston means and the interior of said forward section forwardly of said forward section packing means; and a lateral port in said barrel adjacent the forward end of said rearward section for venting the latter to the atmosphere.

2. In apparatus for manipulating a part withina pressure chamber from the exterior of the latter and without the escape of fluid therefrom, the combination comprising: a barrel having an open forward end; means at said end for detachably connecting said barrel fluid-tight to a pressure chamber in communication with the interior thereof; a plunger extending through and independently reciprocable and rotatable in saidbarrel for demountably carrying a part on the forward end of said plunger and manipulating thev part within the chamber by manipulation of the rearward end of said plunger .exteriorly of said barrel, a section of the length of said barrel being interiorly enlarged to define a cylinder having end walls through which said plunger extends; means providing seals between said plunger and said end walls; piston means on said plunger within and cooperating with said cylinder to provide forward and rearward chambers therewithin; conduit means connecting said rearward chamber with the interior of said barrel forwardly of said seal between said plunger and the cylinder forward end wall; and means for venting said forward chamber to atmosphere, whereby the force developed by chamber pressure acting effectively on the cross-sectional area of said plunger at said forward end wall seal to urge said plunger rearwardly may be substantially counteracted by the force developed by chamber pressure in said rearward chamber acting on said piston to urge said plunger forwardly. '3. The structuredefined in claim 2 in which the con duit means includes a passageway through the plunger.

4. In apparatus for manipulating a part within a pressure chamber from the exterior of the latter and without the escape of fluid therefrom, the combination comprising: means detachably connectable to a pressure chamber to form a portion of thewall'thereof; plunger means sealingly extending through said wall portion and independently reciprocable and rotatable relative thereto for demountably carrying and manipulating a part within the The forward end of the bore 52 is enlarged, as at 78,

and at this point the barrel 24 is provided with a lateral port 80 controlled by a bleeder valve 82. This bleeder valve 82 may be used to test the condition of the pressure chamber within the barrel 24, that is, to ascertain whether the plug 42 is fluid-tight, without unscrewing the tool 22 from the adapter 16.

It will thus be seen that the objects of this invention are fully and cfiectively accomplished. It will be realized, however, that various changes may be made in the specific embodiment used to illustrate this invention, without departing from the principles of the latter. Therefore, this invention includes all modifications encompassed by the spirit and scope of the following claims.

We claim: 7

1. Apparatus of the class described comprising: a barrel havng a forward and a rearward section detachably connected thereto; a plunger of lesser diameter than said rearward section independently reciprocable and rotatable in said barrel and projecting out of the rearward end thereof; packing means interposed between said plunger and said barrel adjacent section connectable fluid tight to a pipe,

chamber by manipulating said plunger meansyexteriorly of the chamber; a cylinder. on said wall portion having said plunger means extending longitudinally therethrough; piston means on said plunger means within said cylinder; means for venting said cylinder, inwardly of said piston means, to atmosphere; and conduit means for connecting said cylinder, outwardly beyond said piston means, with the pressure chamber, whereby thepressure force acting on the plunger means to move it outwardly of the chamber, when the wall portion is connected thereto, is counteracted by the pressure force acting on the piston means.

References Cited in the file of this patent UNITED STATES PATENTS 1,486,856 Bech Mar. 18, 1924 1,701,691 Mueller et al. Feb. 12, 1929 ,772,406 Whiton Aug. 5, 1930 ,700 W011 Nov. 24, 1931 96,3 5 Mueller Apr. 2, 1935 ,244 Yancey July 22, 1941 

